Question

Which description is correct for activated CD8+ T-cells?

a. They kill bacteria and fungi.

b. Their effector function is triggered when they can’t detect the expression of HLA class I on the target cell.

c. Their secondary function is to inhibit macrophages and local inflammation.

d. They release molecules onto virally infected cells to kill them.

Answer 1

d. They releases molecules onto virally infected cells to kill them.

Activated CD8+ T cell kills the infected cells via Fas and FasL interactions. Here CD8+ T cells expressed the FasL on the surface of the cells which is bind to the specific receptor Fas. The Fas is present on the infected cells where cytokines are released. When cytotoxic C binds to their target, increases the level of FasL on the surface of cell and binds to Fas which leads to receptor mediated apoptosis. Here caspase-8 also activates series of caspase activator (caspase 3 and caspase7) and initiates cascade of caspase activation.

Here the cascade of molecular events lead to Fas-FasL interaction of CD8+ T cells and destroys the affected cell.